Photoionization studies of benzene-argon complexes with synchrotron VUV radiation

Bing-Ming Cheng,Edward A Walters,J Robb Grover

doi:10.1063/1.5127120

Abstract

Penning ionization of benzene-argon complexes of states corresponding to the two states of (3p)5(4s)1 of argon for which j = 1, at 11.8282 and 11.6237 eV, was studied using synchrotron radiation. Photoion yield curves for complex ions, (C6H6)nArm+, where n = 1, 2 and m = 1–3, for species less than m/e 200 were determined. For n = 1, the peaks are narrow (0.03 eV) and red-shifted (0.06 eV) by essentially the same amounts for all values of m. For n = 2, the peaks are wider (0.22 eV) and blue-shifted (0.07 eV) also for all values of m. In addition, the dissociation energies of C6H6Ar and C6H6Ar+ were measured to be 0.89 ± 0.07 and 1.37 ± 0.08 kcal mol−1 (i.e., 0.039 ± 0.003 and 0.059 ± 0.0035 eV).

Highlights

Complexes of benzene and argon are prototypes of rare gas/aromatic molecule systems
Much effort has been directed at a detailed understanding of the ground state structure and potential energy surface (PES)
The dissociation energy, C6H6–Ar + hν → C6H6 + Ar + e, was measured using the method described in Ref. 35

Summary

Introduction

Complexes of benzene and argon are prototypes of rare gas/aromatic molecule systems. they have been studied extensively, both experimentally and theoretically.Much effort has been directed at a detailed understanding of the ground state structure and potential energy surface (PES). At the lowest nozzle pressures, 251–350 Torr, only two narrow peaks are observed slightly red-shifted (∼0.06 eV) from the positions of the argon atomic transitions [see Table I(a)]. They grow quickly with increasing nozzle pressure such that the narrow and broad peaks are of comparable magnitude at 450 Torr, as shown

Results

Conclusion